off guard

基本解释

Initially caught off guard, Iranian officials were quickly back on the offensive.
猝不及防被抓了个现行，不过伊朗官员很快就回过神来。
The initial phase has been very steep, taking health experts off guard. That might be in part because of the cold weather.
流感的初期阶段很突然，这让健康专家都猝不及防，可能部分原因是由于天气寒冷造成的。
You'll be able to point people to the documentation so that they can see exactly what your design means to them, and you'll never be caught off guard when someone challenges your design decisions.
您能够指示人们参考该文档，以便他们可以确切看到您的设计对他们意味着什么，并且您决不会在某人挑战您的设计决策时失去警惕。

(NO TRANSCRIPTS) The intensity of the quake, which rocked the city for more than a minute, caught many off guard.
At least since the eighteenth century, these lines have been singled out for their beauty and, considering that Milton is describing the hideous demons under Satan's control, the pastoral elegance of this little simile really catches us off guard.
至少从19世纪起，这些句子因为它们的美感经常被单列出来，并被认为是弥尔顿在描述撒旦控制下的可怕的恶魔,这个小比喻诗歌上的优雅,确实使我们毫无防备。
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Baaderbank Analyst Robert Halver says the move caught many investors off guard.

Being caught off guard so easily was very unbecoming for such a seasoned veteran.
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If someone is caught off-guard, they are not expecting a surprise or danger that suddenly occurs.